What must be used to test the cable plant before acceptance or system turn up?

To ensure the integrity and performance of a cabling installation—especially in fiber optic systems—testing is a critical final step before acceptance or turning up the system. Using a light source and power meter, or an optical loss test set, is the preferred method for this task.

This method specifically measures the optical power loss in fiber optic cables, which is crucial as it determines if the transmission remains effective over the distances the cables will cover. These instruments help identify potential issues such as excessive loss, that may arise from poor connectors, bends, or breaks in the fiber. By measuring the amount of light transmitted through the fiber and comparing it to the initial input light level, a technician can accurately assess the integrity of the installation and ensure it meets the required specifications.

On the other hand, while a network analyzer or a signal generator can play important roles in testing and troubleshooting data networks, they are not specifically designed to measure the optical characteristics of fiber optic cables. Similarly, a ringing tester, generally used for verifying electrical connectivity and for testing voice circuits, does not provide the necessary measurements specific to optical fiber performance. Thus, the light source and power meter, or optical loss test set, is the correct choice for testing the cable plant in the context of fiber optics